Black ceramic powder and articles made therefrom

Abstract

 Present intention discloses a novel black ceramic and a method of producing the same. This method uses a variety of industrial wastes and natural ore as starting materials, which has a very very low price and is very easy to obtain therefore greatly decreases the cost of producing black ceramic materials. So present invention provides a possibility to manufacture a large amount of the black ceramic, which can be used in various field such as transfering of heat and light, plastics, coating, rubber, architecture etc.

Description

Field of the invention

[0001] The present invention relates to a black ceramic. More particularly, this invention relates to a method of producing the ceramic power material and the ceramic articles from a variety of industrial wastes and natural metal ores which contain titanium vanadium, chromium and manganese etc, and also relates to the black power and the articles produed by this method.

Background of the invention

[0002] For thousands years ordinary ceramic has been produced from natural ceramic materials. The ceramic materials and articles having special properties, however, have been manufactured from the industrial product materials only since tens years ago. In order to meet the requirement of world wide demand novel ceramic materials have been developed continuously. Black color body possesses a noble speciality, that is the body can absorb light and heat energe at a very high rate, and can emit infrared rays when heated. Because ceramic body is corrosive-resistant, oxidation-resistant, peelling-off-resistant, ageing-resistant, and also can be used at a high temperature. The body further has a good hardnees and other good properties which the other materials rather than ceramic can not compare with. So the black ceramic is much more preferable to be used as an absorbing and emiting elements in the field of transfering between heat energe and light energe. Usually, the black pigment, which is added to a ceramic material for manufacturing a colorred body, is made of the oxides of manganese, cobalt and nickel etc. But those industrial products are expensive, so that it is difficult or even impossible to manufacture the black ceramic articles in large quantity. So the infrared absorbing and emiting elements have to be made, as well- know by coating a layer or ridiating or absorbing material onto a substrate without such activity, such as metal, ceramic of silicon carbide or zircon sand, plastics etc. Though such method can increase the rate of radiating and absorbing, it brings about a lot of problems, such as the coating layer ageing, peelling-off and complex process. Moreover the coating method also has a relativly higher cost. Therefore, to manufacture a black ceramic material and various shape black body having a higher absorbing and radiating rate at a lower cost has been an important object, which has been researched by scientists in the field for many years. The present inventor has unexpectedly found that some of industrial wastes and natural ores can be used in this aspect.

Summary of the invention

[0003] One object of the present invention is to provide a method of producing a black ceramic articles from a variety of industrial wastes and natural ores containing titanium, vanadium, chromium, manganese and other ordinary, element, which is very easy to obtain. Another object of this invention is to provide a black ceramic powder material, which contains 0.1 -20% titanium dioxide by weight. In the third aspect of this invention there is provided various shape black ceramic articles containing at least 0.05 -20% titanium dioxide and a black pigment consisting of the said ceramic powder, which can be used in coating, rubber, plastics, ceramic and any composition which require a black color additive.

Detailed description of the invention

[0004] The most important feature of the method of this invention is that the starting materials have a very very low prices and are very easy to obtain. According to this invention either industrial wastes or natural ores can all be used, even the floating tailings of some suitable ore can also be used. Depending on the selected starting material some additives may be added, but the additive, however, is not nacessary for them at all. The feature of the starting material of this invention is that the total amount of titamium dioxide, vanadium pentoxide, chromium trioxide and manganese oxide existed in the starting material is at least is 3% by weight, and at least 0.1% for titanium dioxide and 0.1% for vanadium pentoxide. The said starting material is referred to the formulated material prior to processing according to this invention. Besides the feature of the starting material, the method of the present invention is very simple and convenient. A conventional process and apparatus in this field can be used and there is no need for special equipment and special processing step.

[0005] The raw materials, which are suitable to be mixed up according to this invention, include industrial wastes such as ferrosilicochromium slag, silicochromium slag, ferroniclcel melting slag, ferro- titanium slag, ferro-tungsten slag, silicomanganese slag, ferrochromium slag, copper-melting slag, pyrite cinder, vanadium residue, chromium slag, rust and corrosion substances of steel or iron and also include various natural ores such as iron ore, sefstromite, chromite and the floated tailings from the above mentioned ores.

[0006] The term " vanadium residue" mentioned above is referred to the residue of impregnating a vanadium slag, which comes from refining step of a liquid iron containing vanadium, which is the product of processing vanatititaniferrous magnetite.

[0007] The above said additives include usual clay, porcelain clay, porcelain stone, earthenware clay, coal clay, shale, coal stone, red mud, boron mud, talcum, titanium slag, lemon slag, furtural slag, methyl cellulose, starch, arabic gum, water glass, binder and some of metal oxides.

[0008] The great quantity of industrial wastes brings about environmental problem, and not only can it not be sold, but also requires a lot of money to treat. The most preferable row materials for present invention are the industrial wastes, among which the vanadium residue, ferroniclcel milting slag, pyrite cinder and chromium slag are mush more preferable. The vanadium residue used as row material can obtain a very good ceramic, and there may be no need for other additives to be incorporated according to our experiments.

[0009] In certain locations, where the suitable natural ore is very easy to obtain or where is near the floating site, both the ore and the tailings can also be used as starting materials. The process for producing the black ceramic powder material of present invention can be any conventional one, such as:

1. mixing directly one or several kinds of said row material, then the mixture is ground to obtain a suitable size black ceramic powder, which is usually less than 20 mesh;

2. the starting material is calcinated above a temperature of 800 C, usually 1000 --1400 C, for 1 --60 min, then ground;

3. first, the starting material is ground into a suitable size powder, then shaped into green body with suitable form, which after being calcinated is ground into a suitable size.

[0010] The black ceramic powder material produced by above mintioned process has a good agglomer- ative property. Shaped by conventional method, it can be calcinated into various articles with various forms.

[0011] Depending on the composition of the starting material, which comprises optionnally additive and also the selected row materials according to its composition, cost and location, the composition of the present invention black ceramic powder may vary in a broad range. But, it should be emphasized that in the powder there exists 0.1 --20% titanium dioxide, 0.1 --20% vanadium pentoxide, or 0.2 --30% titanium dioxide and vanadium pentoxide by weight; and the total amount of vanadium pentoxide, titanium dioxide, chromium trioxide and manganese oxide is at least 3% by weight, or the total amount of titanium dioxide, vanadium pentoxide, chromium trioxide, manganese oxide and iron trioxide is at least 20 % by weight in the powder. Therefor, the black ceramic powder of this invention generally comprises 0.1 --20% vanadium pentoxide, 2 --20% titanium dioxide, 2 --20% manganese oxide, 0.1 --20% chromium trioxide, 20 --80% iron trioxide and other ordinary elements, more preferablly comprises 0.5 --2% vanadium pentoxide, 3 --20% chromium trioxide, 4--15 manganese oxide, 1--20% chromium trioxide, 30 --80% iron trioxide and other ordinary elements. The percentage in the present specification is calculated by weight.

[0012] Other materials may be added during the process of manufacturing the articles of present invention. However, the formed products contain at least a total amount of 1 % of titanium dioxide, vanadium pentoxide, chromium trioxide and manganese oxide, generally, which contain 0.1 --2% vanadium pentoxide, 1 --12% titanium dioxide, 1 --15% manganese oxide, 0.1 --20% chromium trioxide and other oridinary substances.

[0013] The formed black products can have various shapes, and can be used in many applications, such as the infrared radiating elements, heat collector, heat exchanger, heat radiator, liner of a furnace, surface decorative layer of a building and ordinary ceramic articles. The said infrared rediating elements include various infrared heators, infrared generators in the form of plate, tube, convex etc., either with coating or without coating.

[0014] Besides directly making the commercial articles, the black ciramic powder can also be used in various applications as following.

[0015] 

1. Using as a black pigment which can be added into a black glaze or composite coating and any composition which require a black color agent.

2. Using as a heat-absorbing material which can be applied on the wall surfaces of a furnace in order to absorb the heat of the flowing hot atmosphere and transmit it to the objects to be heated.

3. Using as a stable black powder filler which can be applied in plastics and rubber.

4. Using as a black filler which can be used in architecture decorating coating and in manufacturing architecture decorating surface plate.

Example 1.

[0016] The- vanadium residue was directly ground by a ball-mill to 160 mesh powder.

Example 2.

[0017] The vanadium residue was calcinated at 1150 C for 0.5 hour, then ground to 160 mesh powder. The composition of the powder is indicated in the following table.

[0018] 

Example 3.

[0019] Two parts of pyrite cinder powder having a size of 160 mesh ground by a dry method and one part of chromium residue powder having a size of 140 mesh were mixed together with a suitable amount of water. The homogeneous mixture was shaped into a bar form in 10 mm diameter by a conventional means. Then the bars were broken into a cylinder shape in length of 15 -20 mm after drying. The pellets were calcinaed at 1220 C for 10 min, then ground into 160 mesh black powder.

Example 4

[0020] A mixture of 98 parts powder of example 1 and two parts of methyl cellulose with a suitable amount of water was made into a particles in diameter 0.5 --2 mm. 70 parts of clay, 10 parts of arenaceous quartz and 10 parts of feldspar were mixed, and ground into powder. 10 part of the said particles and 90 part of the said powder were mixed, and shaped into a small plate form in 20mm x20mm x 5 mm, then the plates were calcinated at 1200 C for one hour. The product was the small porcelain plate having white base, in which there is a lot of black points.

Example 5

[0021] The black powder of example 2 was used as a filler in polyethylene plastic process to substitute the ordinary filler of carbonate. In conventional process, applying 10% powder of example 2 by weight based on the total amount of the powder and polyethylene, no other black pigment, gave polyethylene products in balck color.

Example 6

[0022] Black ceramic powder of example 1 with a suitable amount of water was applied onto the inner walls of a calcinating furnace, after 24 hours it was subjected to a temperature of 12000 -14000 C and become a black ceramic coating on the surface of the wall. The suitable deepth of the coating was 0.2 -1mm. The method saved 3 -5% energy compared with the case of no heat-absorbing material being applied.

Example 7

[0023] A mixture of 99.5 part powder of example 1, 0.5 parts of methyl cellulose and water was shaped, dried, and calcinated at 1120 C for one hour. The radiating rate of the produced ceramic tube having an outer diameter of 31 mm, inner diameter of 25 mm, hight of 40 mm was 0.84 - 0.86 at 500 -600 C.

Example 8

[0024] A mixture of 60 parts black ceramic powder of example 2, 20 parts clay, 10 part talcum powder and 0.5 parts sodium carbonate was ground with a ball-mill, then shaped, dried, calcinated at 1100 C for one hour. The radiating rate of the produced tube having an outer diameter of 32 mm, inner diameter of 25 mm and length of 1000 mm was 0.8394 --0.8620 at 500 --600 C.

Example 9

[0025] A mixture of 7 part ceramic powder of example 3 and 3 parts of 80 mesh clay powder was shaped and calcinated at 1170 C for 6 hours. The rediating rate of the obtained black ceramic body is 0.857 --0.867 at 500 --600 C.

Example 10

[0026] The mixture of example 8 was prapared into a pulp, then was poured into a mould wherein a electrothermal wire was already disposed. Shaped article was calcinated at 1100 C for 1 hour. The product is core-type infrared element having a diameter of 15 mm, length of 400 mm and electric work rate of 300 W.

Example 11.

[0027] The mixture of example 8 was. shaped by moulding, then dried, calcinated at 1100 C for 1 hour. Product was black solar energe collector, which was a tank with inlet and outlet for water, and had a length of 640 mm, wideth of 420 mm, hight of 70 mm, and wall thickness of 3 mm.

Example 12

[0028] A mixture of 60 parts ceramic powder of example 2 and 40 parts clay powder of 80 mesh was shaped and calcinated at 1140 C for 2 hours. The product was a 100 mm x 100 mm x 8 mm cerimic plate in black color.

Example 13

[0029] The mixture of example 8 was prapared into pulp with water. The pulp was poured into a mould, which was able to mould the pulp into the shape of a figue. After releasing it was dried and calcinated at 1100 C for one hour. The product has a hights of 300 mm, a thickness of the wall of 2mm.

[0030] The features disclosed in the foregoing description and in the following claims may, both separately and in any combination thereof, be material for realising the invention in diverse forms thereof.

Claims

1. A method of producing a black ceramic powder material and a black ceramic body containing the power by means of conventional technique, wherein the improvement comprises using industrial wastes and/or natural ores, optionally together with additive as starting material which contains at least 0.1 -20 w.t.% titanium dioxide.

2. A method according to claim 1, wherein the said industrial wastes comprise ferro-silicochromium slag, ferroniclcel melting slag, ferro-titanium slag, ferrotungsten slag, silicomanganese slag, ferrochromium slag, copper-melting slag, pyrite cinder, vanadium residue, chromium slag, rust and corrosion substances of steel or iron; the said natural ores comprise iron ore, sefstromite, titaniferous magnetite, vanadititaniferous maganetite, chromite and the tailings from above ores, the said additives comprise usual clay, porcelain clay, porcelain stone, earthenware clay., coal clay, shale, coal stone, red mud, boron mud, talcum, titanium slag, lemon slag, furfural slag, methyl cellulose, starch, arabic gum, water glass, various binder and some of metal oxides.

3. A method according to claim 2, wherein the said starting material is selected from a group consisting of ferro-tungsten slag, vanadium residue, silicochromium slag, ferrotitanium slag, ferroniclcel melting slag, pyrite cinder, copper-melting slag and chromium residue.

4. A method according to claim 3, wherein the said starting material is selected from a group consisting of vanadium residue, ferroniclcel melting slag, pyrite cinder and chromium residue.

5. A black ceramic powder material, which comprises 0.1 --20% titanium dioxide by weight.

6. A black ceramic powder material according to claim 5, which comprises at least 0.5 --15% titanium dioxide by weight.

7. A black ceramic powder material according to claim 5, which further comprises at least 0.1 --20% vanadium pentoxide by weight.

8. A black ceramic powder material according to claim 7, which comprises at least 0.2 -3% vanadium pentoxide by weight. ₁

9. A black ceramic powder material according to claim 5, which comprises at least 0.2 --30 % by weight of titamium dioxide and vanadium pentoxide.

10. A black ceramic powder material according to claim 9, which comprises at least 2 -25% by weight of titanium dioxide and vanadium pentoxide.

11. A black ceramic powder material according to claim 9, which further comprises chromium trioxide and manganese oxide, and the total amount of titanium dioxide, vanadium pentoxide, manganese oxide and chromium trioxide is at least 3% by weight.

12. A black ceramic powder material according to claim 11, which further comprises iron trioxide, and the total amount of titanium dioxide, vanadium petoxide, manganese oxide, chromium trioxide and iron trioxide is at least 20% by weight.

13. A black ceramic powder material according to claim 12, which comprises 0.1 -20% vanadium pentoxide, 2-20% titanium dioxide, 2 -20% manganese oxide, 0.1 --20% chromium trioxide and 20 --80% iron trioxide by weight.

14. A black ceramic powder material according to claim 13, which comprises 0.5 --2% vanadium pentoxide, 3 --20% titanium dioxide, 4 -15% manganese oxide 1 --20% chromium trioxide and 30 --80% iron trioxide by weight.

15. A ceramic article made from the black ceramic power material, which comprises at least 1% by weight of vanadium pentoxide, tatanium dioxide, chromium trioxide and manganese oxide.

16. A ceramic article according to claim 15, which comprises at least 10% by weight of vanadium pentoxide, titanium dioxide, chromium trioxide, manganese oxide and iron trioxide.

17. A ceramic article according to claim 16, which comprises 0.1 --2% vanadium pentoxide, 1 -12% titanium dioxide, 1-15% manganese oxide, 0.1-20 chromium trioxide, 5--60% iron trioxide by weight.

18. A ceramic articles according to claim 17, wherein the said articles comprise an infrared radiating and absorbing element, heat collector, heat exchanger, heat radiater, liner of a furnace, surface plate and ordinary articles.

19. A ceramic article according to claim 18, wherein the said infrared radiating element comprises various infrared heator and infuared genara- tor in a form of plate, tube or convex.

20. A method of using the black ceramic powder material defined in claims 5 comprising using which as

(1) a black pigment,

(2) a black filling material,

(3) a black heat or light absorbing material,

(4) a blak heat radiating material.